The first method I posted to remain mobile with a USB powered audio interface involved a cable like this one:

Now, for this method, get your hands on a cable like this one:

NOTE: Not all cables are alike. I tried some that did not work. But the ones that did, have these types of specs on them:

This method has worked on all the un-powered USB hubs that I have; so you choose the one you like. BUT*:

*BUT, I would strongly recommend the USB hubs that have a switch to stop the iOS device from trying to deliver power to the hub. When I tried these hubs, I never got an error from the iOS device stating that it can not deliver power to the audio interface:

If you choose a hub like these, keep the switch in the OFF position.

And you will need a portable mobile phone charger similar to these ones:

So, lets get to it.

First step: Power up the USB hub.

Second step: Power up the audio interface. A Mackie Onyx Blackjack in this example.

And here is this setup Phantom powering a pair of Rode M3 microphones using Auria:

Now, that's not all. Because for the same price, if you have another iOS 7 capable iphone or ipod, you can use them also with the same setup. NO JAILBREAK REQUIRED. Yes, you read well, NO JAILBREAK REQUIRED. So, here is an iPhone 4S running iOS 8.1 with a 30pin to USB CCK using the same setup and MultitrackDAW:

LOL. No. As far as I know, you cant power your iOS device with CCK methods. Only with some MFI devices.

But you could try with a larger ampere power supply. I have not tried it because I don't have one. A 5V 3,5A at least. But I cant take resposibility if your burn some electronics in the process. So, please, if you try it, on your own risk.